Persistence of sub-clinical Batrachochytrium dendrobatidis infection in stream anurans in South Asia
Data files
Oct 09, 2025 version files 229.83 KB
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Field_Data_2018_to_2020.xlsx
228.37 KB
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README.md
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Abstract
Chytridiomycosis is caused by Batrachochytrium dendrobatidis (Bd) and contributes significantly to amphibian declines globally. It has affected more than 500 amphibian species on five continents. In South Asia, the Western Ghats is an amphibian biodiversity hotspot; however, the population status of anurans and their burden of chytridiomycosis are not well understood. Our aim was to understand pathogen prevalence, load, and its persistence in a stream anuran community in the Western Ghats. We carried out a capture-mark-recapture (CMR) programme in five ephemeral streams of the Tillari Conservation Reserve (TCR), Western Ghats, India, from 2018 to 2020 during the early (wet) and late (dry) recovery periods. We used quantitative Polymerase Chain Reaction (qPCR) to assign disease states - no (N), low (L), and High (H) levels to every anuran, based on the Bd loads detected. We constructed population models using CMR data from skittering frogs, with Program MARK, and estimated transition probability, apparent survival probability, and capture probability in each disease state. We found that the overall Bd prevalence was 74.6% in the community, with an average infection load of 49 to 700 zoospores/swab. Many anurans cleared infections between early (wet) and late (dry) recovery periods, while some maintained high infection loads. In skittering frogs, the infection states did not influence capture probabilities and apparent survival probabilities. The transition probability between infection states was random, and transitions from any disease state to low were more probable than transitions from any disease state to high or no disease states. The maintenance of a substantial burden of Bd in the anuran community with no apparent impact on their survival or capture probabilities suggests an effective pathogen transmission mechanism. As anurans continue to show a declining trend in the Asian tropics, investigation on the impacts of sub-clinical Bd infections in anurans needs impetus.
Dataset DOI: 10.5061/dryad.1zcrjdg5v
Description of the data and file structure
File: Field_Data_2018_to_2020.xlsx
It contains data used for capture mark recapture of frogs from 5 stream segments in Tillari Conservation Reserve, Maharashtra, India, from 2018-2020. The data represent frogs that were captured and marked, and recaptured, that were > 29 mm in snout vent length. Descriptions of the data are given below.
Session : Odd numbers are Wet session, and even numbers are Dry session
Stream : HB_Hevale Bridge, KA_Kharade, HV_Hevale village, GW_Ghatiwade, RW_Raniwade
Visit : Total 5 visits each session
R_N : Recapture( R ), and New Capture ( N )
Swabb : Yes taken ( Y ), and Not taken ( N )
Wt : Weight in grams
SVL : Snout to Vent length in mm
T : Vertical transect quadrant number
B : Horizontal transect quadrant number
DNA Serial No : DNA Serial No for DNA samples
Mean Cp : qPCR Cp values
Year : Year of collection
Disease State : Positive ( P ), Negative ( N ), Not applicable ( NA )
Species : EC = Euphlyctis cyanophlyctis, IS = Indosylvirana caesari, InC = Indirana chiravasi, NJ = Nyctibatrachus jog
Code/software
MARK, R version 4.4.1
Access information
Other publicly accessible locations of the data:
- Not applicable
Data was derived from the following sources:
- Not applicable
